A file ending in is the first piece of a split 7-Zip archive. When a single compressed file is too large for certain storage or transfer limits (like email attachments), 7-Zip breaks it into multiple sequential parts named .001 , .002 , .003 , etc. Key Identification Details
: Right-click specifically on the file ending in .001 .
: A .7z.001 file is not a complete archive on its own; it contains only the starting data.
: To successfully open or extract the contents, you must have all parts of the split archive (e.g., up to .7z.009 ) saved in the same folder . How to Extract a Split Archive
: The software will automatically detect and join the subsequent parts ( .002 , .003 , etc.) to rebuild and extract the original file. Troubleshooting How to extract part files 001 using 7zip on windows (2026)
: Use the 7-Zip context menu to select "Extract to [Folder Name]" or "Extract Here" .